republicans mitch mcconnell and john boehner. those four members of congress are expected to make the drive from the capital, which you see on the right, down pennsylvania avenue, to the white house, there on the left. and we expect them to enter through a side door on the west side of the mansion. that's the entrance right there. and they'll meet with the president. in the oval office. beginning, we're told, at 3:00 p.m., less than one hour from now. and just four days ahead of the so-called fiscal cliff. so a very big moment in the nation's capital. and to walk us through what might happen we turn to jessica yellin, a chief white house correspondent. jessica, we said up front, it is a long shot, give us a best case scenario. >> reporter: the best case scenario would be that all the leaders walk out of this meeting and say they have a deal. the two senators say they can bring it to a vote, and none of their members will filibuster it. house speaker john boehner says he will bring it to the house floor for a vote before new year'